Hi, E3D here. We need to talk to you about groovemount.

TL;DR:

Groovemount is okay, but it's a hangover from when 3D printers were made in sheds. They aren’t any more, so we’re offering an alternative, using screw threads. If you think this would suit your printer better you can buy one here(1.75mm, suitable for bowden or direct systems).

We’d also really like to get your feedback. Establishing a standard is not something that should be taken lightly. In order to create a healthy enduring standard we want to consult and involve the whole community.

If you want to know more about the issues with groovemount and why we’re offering a threaded alternative, read on.

What’s the problem?

Here at E3D we’ve used always used groovemount on our HotEnds as the means of attachment. It's been the standard way to mount a HotEnd on a printer since the makergear standard was introduced. When introduced, it was intended for attaching a HotEnd to a piece of laser cut wood (an application that isn’t especially common any more). It’s a method well-suited to making prototypes as it needs a minimum of skills and lathing tools, but it does have a few issues:

Relying on 2 parts that simply push together requires that the parts are really precisely made. Even slight variation can result in a poor fit, with heat sinks that are either hard to push into a bracket or that wobble around during printing. We do our best to avoid this by using good machinists and doing random spot checks, but it’s still an issue we’d like to eliminate completely.

Mounting brackets can wear down from repeated removal and replacement of the HotEnd, leading to a once well-fitting HotEnd becoming wobbly.

While these issues don’t make groovemount unusable, we think it might be time for a new approach.

Apart from anything else, it looks great.

The solution

We’ve thrown around a few ideas, but one that we’d like to take forward is a little… screwy. And by that we mean that we’ve put a screw thread on to the top of the heatsink. It’s hardly a candidate for the hackaday prize, we know, but by god it is just so much better! Using a screw thread has several advantages.

They can be very reliably and repeatably machined and quality controlled.

They wear incredibly slowly, so you can take out the hotend, tinker and replace as much as you want and the hotend will still be held securely.

We think threads give you more versatility in mounting options, giving you the choice of mounting through a plate of any thickness you want (up to 5 mm) or screwing into a 3d printed socket (tapped or printed threads).

Some data about the parts:

Identical performance to standard heatsinks

Uses M12x1.5 thread for the main thread (this could change depending on feedback)

Same overall height as a standard heatsink

We’ve already done some alpha testing, and there are threaded V6 heat sinks being put to the test out in the wild. Check out David Crocker’s PCB delta printer, which has been using this HotEnd for a while now.

However, we sadly don’t have every type and make of 3D printer available in-house to test our new mounting solution on, and that’s where you come in.

We need you!

We are releasing this product in beta (1.75mm only, suitable for bowden or direct systems), and want to hear from you the user how you want to mount your HotEnds . We’ve chosen threads as we think they are a versatile solution and translate well to manufacture but are open to more suggestions. Use the hashtag #screwyV6 on Twitter to tell us what you think, or feel free to message us on Facebook!

I would like to see flats on the heat sink body to tighten it into its mating part. And if you are expecting metal on metal contact then perhaps an integrated nylon thread lock feature on the threads themselves.

I'm bachelor in mechanical engineer and I'm developing big 3D printers for fast acceleration rate.
I think this is a good direction in extruder mounting, but I think that vibrations can cause a fail with this system. I don't know how much is the threaded part, but probably using a nylon lock nut or a double nuts solution, this problem maybe produce less failing/problems.
I think the thread M12x1.5 is good, in particular because is the same of inductive sensors, that are using in a large number of printers.

Sorry for my english, and congratulations for your job, in particular in R&D.

I have a Rostock Max V3 from SeeMeCNC. I would love to be able to use a V6 in the hot end. The current hot end, HE280, has an accelerator probe as a component. A nice way to plug the V6 in to the hot end or a quick replacement (there are 9 wires that need to be plugged in with a plug that can come lose, it would be great to have a better connector as well...). Currently repairing the HE280 take lots of skill and good eyesight. I just turned 69 and my fine motor skills as well as my eyesight aren't what they used to be so I am spending more money having thermistors replaced than I should have to. I am willing to be a beta tester if you have any solutions for the Rostock Max. Thanks for taking the time to read this.

I own 6 3d printers and I'm currently making the seventh. One delta, 2 xy intelligent core, one prusa - are DIY. Purchased 2 Vell...
Više
Hi,
I own 6 3d printers and I'm currently making the seventh. One delta, 2 smartrapcore, one big prusa -all are DIY. Purchased 2 Velleman k8200 and the Ultimaker 2 extended in production. It would be a good idea to try out your innovations.
Thnx in advance

I definitely agree!
My hotend likes to spin around a bit, and it makes keeping the wiring neat and tidy almost impossible!
However with this implementation, I'm finding it difficult to imagine how it is going to integrate with just 3d printed parts (let's be honest, if we can get away without using extra hardware, we will!) and if it starts to come loose, isn't that going to slightly lower the nozzle height, which could spell for some very messy prints!

Excited to see you guys start to mix up your classic bit of design though, maybe you can look at remote direct drive extruders next ;)

My concern here would be 3d printed mount support. The size of the groove mount assured 3d printed mount stability. Judging by the picture in this article, the pcb is the ideal thickness of the mounting bracket, which works well here and on metal brackets, but can the user easily print such a thin mount and still maintain stability? I'm curious to see also if there is any deflection during motion with a 3d printed mount out of petg, abs, or the like. If it is not sturdy enough, the ens user would have to integrate a threaded nut, which would have to be far more precise than a groove mount.

Anyways, I'm nobody, not really looking to beta, just making an observation.

This solution is really quite brilliant. You definitely hit the nail on the head as far as solving the bowden side anyway. As for direct, well I suppose you could adapt an extruder so this screws into it, but I could see a lot of issues coming up there which may introduce slop. I feel like for a direct drive system, if anyone wants to go E3D they should be using the titan aero. It would be more practical anyway so I don't think there is much of a reason to even gear this new hotend mounting system towards direct drive users.

One concern I may have is fully constraining the hotend in its mounting hole, as well as preventing rotation. Perhaps going with a longer collar above the lip, maybe 3mm tall, to provide better locating within the hole. Giving this a slight chamfer and removing that lip may work better, although it would increase the cost and complexity of required mounting plates so maybe its best to just keep it simple and not perfectly constrained. The best way to prevent rotation would probably be to supply low profile M12 nylon locking nuts along with the hotend, allowing users to keep high tension at all times and reduce the chance of a slip. Alternatively, adding a vertical groove (or many) in the collar mentioned previously could optionally be used by manufacturers looking to ensure the hotend is locked and will not rotate, but will not affect others who don't care and don't want to bother putting a locating groove in their carriage.

I look forward to seeing what E3D comes up with in the future. And if E3D ever needs products tested, I'd be happy to help ;)

Great idea. I am just in the process of fitting a new effector to my delta and designing a stable mount for the hot end has been a bit of a pain. I use a Nimble extruder and an adapter to fit it would be easy with a screw in hot end.

Why not just make threaded the new standard? And have backwards compatibility through an adaptor that threads on and makes it a groove mount - locked in place with a set screw or some Loctite? I like it - but having 1 product that "just works" is why I come back to you folks. Having 1 product that fulfills 2 rolls is even better in my opinion.

Moving away from the groove mount is an excellent idea. The downside of a screw mount, however, is the nozzle z-height would be determined by torque. This means removal and re-insertion of the hotend would require re-calibration of the z height for precise first-layer height control (unless everyone moves to something like a piezo z-sensor, so the nozzle tip becomes the bed probe).

A bayonet mount is superior in this regard. Camera manufacturers long ago made the move from screw mounts to bayonet mounts to achieve consistent z alignment (in their case for focus reasons).

Please consider a bayonet mount. If you were to sell BOTH the hotend and the bayonet ring plate (with screw holes for mounting it), it would be easy for printer manufacturers to incorporate it in to their designs.

I see the issue of loosening over time. Two thin nuts instead of one larger nut would allow locking the hotend in place. I love the idea of a threaded design as I could thread my mounting plate and use a thin nut to lock in place. The course thread also looks like it could be printed or tapped into a printed mount quite easily. Great job as usual.

For heaven's sake please machine two flat sides on the cooling fins. That way we can tighten the screw more effectively by holding the Heat Sink with a spanner or plier. I always have problem removing my heatbreak when the thread seize with the Heat Sink. There is just no way for me to grip the heat sink effectively with the perfectly round fins. You don't have to machine all the fins. Machining two shallow flat sides on two or three fins that will be just enough for us to grip it with a spanner or plier. That wouldn't affect the cooling, would it?

This is actually something we've considered, and you're right in that it wouldn't affect the cooling. The problem is that it would affect the cost and our lead times, as the machining would become more complex and slower.

For heaven's sake, please machine two flat sides on two or three of the fins. That will provide a grip for a spanner or plier and makes it more effective in tightening the nut. Sometimes I have problem releasing my heat break when it's thread seize with that of the heat sink.

Just machine parallel flat sides on two or three of the cooling fins wouldn't affect the cooling, would it?

Does that mean a nylon (plastic) nut to avoid wear of the aluminium and it's coating?

What if the carriage is made of a less than super rigid material (eg it's 3d-printed) and so the constructor wants to make it a little thicker? Will there be enough length on the heatsink shaft to allow this (given thick nut)?

Is the nut sufficiently self-locking or are two required?

Will there be a spanner supplied for the nut?

Will the need for spanner interventions from above allow a wide range of carriage designs?

I have V6s on two of my printers and I do like their simplicity in mounting. I can see pros and cons for the screw mount. One of my printers would easily accept a screw mount but the other would take the development of a new bracket. Now if the screw mount came with some sort of collet that could convert an existing mount, preferably made out of aluminium I am sure that you would have a lot of buyers. A lot of CR10 owners have already invested time and money creating V6 mounts both by printing and machining Aluminium mounts, which if they could be reused it would make a lot of people happy. I would also suggest the nut it is made out of aluminium rather than plastic.

I'm not sure that this is ideal. By using a thread, orienting the heat block (and wiring) becomes less predictable especially when access to the top securing nut is not possible. For example if the heatsink is screwed directly into an extruder.
Perhaps a good compromise would be to machine a flat onto the threaded area. The user would then have the option to simply insert the headsink into a round hole (with a flat) and then tighten a setscrew to lock it in place. This controls Z height and orientation...
In general, I'm a big fan of the 'old school' groovemount - it's simple and it just works.

I'm a long-time RepRapper and I prefer direct-drive extruders, so groove-mount hotends have always been my bread-and-butter. A threaded connection would definitely be more stable and a bit easier to swap out than a groove-mount, but I'm worried that printing a threaded connection might be tough to make on some people's printers. However, M12 is probably big enough to print well even with a moderately crummy printer.

Also, I'd like to echo Andrew DeGonge's comment about the screw connection becoming loose: a mounting point with a nylon insert should be fine, but then the problem would become screwing it in to the correct torque without denting the side of the heatbreak with a wrench!

This solution works brilliant - I use exactly this concept since several weeks with a 2.85 custom hotend on my big delta (printing area 400*600mm). Leveling and calibration with the nozzle (based on duet wifi and smart effector) is always perfect, especially after changing the nozzle or the whole hotend ...
After four years (daily) printing with delta printers - this solution is my first choice ... congratulation - well done

Your design cries out for the use of a belleville spring washer. Belleville washers are ideal for securing to plastic or pwbs. They keep a constant load under temperature, vibration and plastic creep. One could be used under the nut or with proper design on the hotend side of a direct system.

The only disadvantage is a little engineering is required to select the right size, material, vendor etc. and you probably need to provide the washers so the user doesn't have to source them. Be careful of supplier. Some provide washers with incorrect geometry or especially weak materials that don't spring back correctly.

I like the idea of having a series of radial grooves or ridges on the mounting flange to resist rotation and add bite. This could be paired with a locking / grooved nut to secure. M12x1.5 thread seems fine, but an additional couple millimeters of thread length would be preferred to allow for mounting to printed effectors and still using the locking nut. A 5mm thick printed effector may not be stiff enough for every circumstance.

Prefer that it not thread into extruder for direct drive, use the nut - so can change hotend just moving straight up/down.
While you're at it could we have some kind of connector that uses standard crimps (so we can assemble each side) and handles heater, thermistor and fan all neat and together? Again so that we can shift the complete hotend in/out easily.
Probably some thought went into the 12.5 thread, but seems like M12 is bog standard easy to get for us DIY end users? Also (not sure about the measurements here) seems like the current mount is 12mm so if you matched that people would have easier time putting into the old style mounts?

Id actually like to see clamp type holder. It would make setting height soooo easy, especially with dual extruder setups. When I was still building printers, I use to lathed down the groove mount so it was 12mm smooth trough all and mount it into aluminium block (clamp style), witch also served as additional cooler.
But again, I dont build printers anymore, so my opinion doesent count much.

As it has already been suggested, I think that a couple of features would improve a lot the design:

* Use the more standard M12x1.75 thread to make easier to use the heatsink in conjunction with other components more readily available or easier to source.
* Add two flats to be able to screw the heatsink with a wrench.

going away from grove mount is ok, but if you are making new standard make a better one. for e.g. add bed leveling piezo sensor into new mount... if you just want screw then thin it out so you can screw adapter on it and have grove mount compatibility when needed

I have to agree with the idea of using the M12 1.75 as standard since it shares commonality with many sensors. +1 for the belleville spring washer.

Bayonet mount would indeed be ultra precise, guess it depends on the level of "slop" we could live with. Personally I think it would be overkill.
Also it's obviously ~way~ more costly and much harder for the hobbyists / low cost communities to design and build mounts so it's probably a non-starter.

I had an idea that occurred regarding the "cut a flat for a wrench / spanner on the fins" idea. Also obviously a good idea, but does add machining / cost.

What if instead you use this low tech solution - included with every HotEnd a small square or rectangular silicone rubber sheet to wrap around the fins for grip. I'd say about 1.5mm thick so it's nice and cushy. Cost would be negligible, I can get a 12" square here in the US for $1. You could even use company colors ;-) ...

Love, love, LOVE you're trying to hammer out a standard. It's time 3D printing grew up a bit. Would be willing to beta as well.

I agree it's time for the groovemount to be replaced. However I think this should go beyond just replacing the attachment mechanism. I think the whole cylindrical based heatsink is an ecological dead end. A cylindrical-based heatsink is hard to mount, requires and adapter to attach the cooling fan, and necessitates a screw-in heat break.

A cuboid based heatsink is a much better approach. And you already have one - the chimera/cyclops heatsink. This allows direct mounting, easy attachment of a fan (without using an adapter), and a slide-in heat break.

So what I think you should do is produce a variant of the chimera/cyclops heatsink that is designed for a single extruder. (This would also make it easier for users to upgrade to dual extrusion.)

I agree that the groovemount is a hangover that needs replacing. However I don't think your redesign goes far enough. In my view the entire cylindrical-based heatsink is an ecological dead end and needs replacing. A cylindrical-based heatsink is hard to mount, requires an adaptor to attach a fan and requires a screw-in heatbreak. A cuboid-based heatsink has none of these disadvantages and what's more you already have a design - the cyclops/chimera heatsink. All you need to do is produce a single extrusion version of the cyclops/chimera heatsink. (This would have the added advantage that it would simplify the process of upgrading from single to dual extrusion).

Why not mount it from the back, like for example the chimera or cyclops. I think this has the advantage of a short lever between the nozzle and the mounting poing, resulting in a much stiffer system. I always wondered why there is no mounting option at the lower end of the v6 heatsink.